Account status determines whether users can log in and receive mail. The account status can be viewed in the Account list shown on content pane or from individual accounts, General Information tab.
The following account statuses can be set
Active. Active is the normal status for a mailbox account. Mail is delivered and users can log into the client interface.
Maintenance. When a mailbox status is maintenance, login is disabled and mail addressed to the account is queued at the MTA.
Locked. When a mailbox status is locked, the login is disabled until you unlock the account, but mail is still delivered to the account. Locked can be set if you suspect that a mail account has been hacked or is being used in an unauthorized manner.
Closed. When a mailbox status is closed, the login is disabled. This status is used to soft-delete an account. The account exists until you delete it.
Pending. When a mailbox status is pending, login is disabled and mail cannot be received.
Go to Manage>Accounts..
Select the account to edit and in the gear icon click Edit.
Click the General Information page.
From the Accounts status list, select the desired status.
Click Save.
The new account status takes effect immediately.